Multi-axle semi-trailer type transport vehicles, to which the present invention relates, are generally known as exemplified by the teachings of J.A. Ranta U.S. Pat. No. 2,819,911 issued Jan. 14, 1958 and J. Perrotin U.S. Pat. No. 3,903,979 issued Sept. 9, 1975. Other patents to which reference may be had are as follows: U.S. Pat. Nos. 2,968,495 issued Jan. 17, 1961; 3,689,107 issued Sept. 5, 1972; 3,690,698 issued Sept. 12, 1972; 3,734,538 issued May 22, 1973; 3,930,669 issued Jan. 6, 1976; 4,165,005 issued Aug. 21, 1979 and 4,468,047 issued Aug. 28, 1984.
The present invention is directed particularly to an improvement over the latter U.S. Pat. No. 4,468,047 and results from adapting such disclosed apparatus for transport of substantially heavier loads. The apparatus of the present invention is intended for carrying pay-loads of up to say 1 M lbs., which as a rolling load, is difficult to design because of municipal, provincial and/or state laws regarding permitted loads on public road ways and highways.
One of the many difficulties in multi-axle, multi-wheel transport systems is distribution of the load evenly amongst the many wheels and one of the objects of the present invention is to provide an apparatus that generally overcomes such difficulty.
A further difficulty of multi-axle, multi-wheel vehicles is that they become rather lengthy rending them difficult to maneuver on public roads designed for more conventional transport systems and an object of the present invention is to provide, in addition to equal distribution of weight from one wheel system to another, means to steer the system and also controllably distribute the load.
In travelling, for example, from one place to another, it is desirable to have a soft ride so as not to impose undue impact by the rolling loads on the road carrying surface and/or the apparatus rolling on said surface and this soft ride can be provided in a lengthwise direction, but on the other hand it is desirable to have a stiff ride in the direction transverse to the travel direction so as to give stability to the travelling load. Another object of the present invention is to provide a multi-axle, multi-wheel transport vehicle with controllable ride characteristics.